1. Field of the Invention
The present invention relates to a stereoscopic image display and a method for driving the same.
2. Discussion of the Related Art
A stereoscopic image display is classified into a display using a stereoscopic technique and a display using an autostereoscopic technique.
The stereoscopic technique, which uses a parallax image between left and right eyes of a user with a high stereoscopic effect, includes a glasses type method and a non-glasses type method. In the glasses type method, the parallax image between the left and right eyes is displayed on a direct-view display or a projector through a change in a polarization direction of the left and right parallax image or in a time-division manner, and thus a stereoscopic image is implemented using polarization glasses or shutter glasses. In the non-glasses type method, an optical axis of the parallax image between the left and right eyes is separated generally using an optical plate such as a parallax barrier and a lenticular lens, and thus the stereoscopic image is implemented.
U.S. Pat. No. 5,821,989 and US Publication No. 2007022949A1 are known to disclose an example of the glasses type stereoscopic image display.
FIG. 1 schematically illustrates a glasses type stereoscopic image display. In FIG. 1, a black region of shutter glasses ST represents a shutter that blocks light traveling toward an observer (i.e., viewer), and a white region of the shutter glasses ST represents a shutter allowing transmission of light toward the observer. When a liquid crystal display element is selected as a display element DIS, a backlight unit providing light to the display element DIS is necessary.
As shown in FIG. 1, during odd-numbered frame periods, left eye image data RGBL is written to the display element DIS, and a left eye shutter STL of the shutter glasses ST is open. During even-numbered frame periods, right eye image data RGBR is written to the display element DIS, and a right eye shutter STR of the shutter glasses ST is open. Thus, the observer can view only a left eye image during the odd-numbered frame periods and only a right eye image during the even-numbered periods, thereby obtaining a stereoscopic feeling.
The display element DIS may display a two-dimensional image (hereinafter to as “2D image”) in a 2D mode and may display a three-dimensional image (hereinafter to as “3D image”) in a 3D mode.
When the related art stereoscopic image display reproduces the 2D image, the related art stereoscopic image display is driven in the same method as the related art driving method. When the related art stereoscopic image display reproduces the 3D image in which a left eye image and a right eye image are divided in time and/or space, the related art stereoscopic image display is driven in a driving method different from the related art driving method. Because of this, if the related art stereoscopic image display converts a data voltage of the 2D image and a data voltage of the 3D image based on the same gamma compensation voltage, gamma characteristics of the 2D image and gamma characteristics of the 3D image may vary. For example, if gamma characteristics of the related art stereoscopic image display are optimized based on the reproduction quality of the 2D image, the gamma characteristics of the 3D image may not be optimized. Accordingly, a brightness perception of the 2D image the user perceives and a brightness perception of the 3D image the user perceives vary.